1. Field of the Invention
The invention relates to waste water treatment. Specifically, the invention relates to ensuring that a proper amount of an agent is associated with water and waste water during treatment.
2. Discussion of Related Art
Water and wastewater treatment processes typically introduce into an aqueous solution to be treated a disinfectant or biocidal agent, such as bromine or chlorine. Chlorine perhaps is the most common water and wastewater agent used throughout the world, today. Large wastewater treatment plants commonly use chlorine gas or liquid. Small plants, such as home wastewater treatment plants and some commercial wastewater treatment plants use chlorine tablets, composed of mainly calcium hypochlorite.
A variety of techniques are known or used for introducing these and other agents into an aqueous solution. Some treatment processes involve manually adding a liquid or granular agent to the solution. A drawback to this method is exposing the person handling the agent to potentially hazardous chemicals. Another drawback is the deterioration of the activeness of the agent when exposed to ambient conditions, such as humidity.
Some processes employ an agent distributor, such as a dissolve- or erosion-type flow-through feeder. Dissolve/erosion-type feeders typically introduce low-solubility agents into aqueous systems. Generally, dissolve/erosion feeders operate by establishing a flow of solution through the feeder to cause surface friction between the solution and the agent granules or tablets, thereby eroding the surfaces thereof and dissolving the displaced particles. See, for example, U.S. Pat. No. 5,405,540, issued Apr. 11, 1995, to N. Tang. Some apparatuses and processes monitor the amount of agent dispensed. See, for example, U.S. Pat. No. 5,064,531, issued Nov. 12, 1991, to L. K. Wang et al. However, a significant drawback of these dissolve/erosion-type feeders is, because granule/tablet dissolution rate is dependent on solution temperature and flow rate, inter alia, the difficulty in predicting agent quantity requirements.
To better control the amount of agent dispensed, an agent feeder has been positioned in a container in which solution level and flow rate therethrough are controlled. However, the mechanisms for doing so do not lend to critical, incremental adjustments. See, for example, U.S. Pat. No. 3,595,786, issued Jul. 27, 1971, to R. J. Horvath et al. and U.S. Pat. No. 4,759,907, issued Jul. 26, 1988, to R. J. Kawolics el al.
Some devices indicate agent level. See, for example, U.S. Pat. No. 4,986,902, issued Jan. 22, 1991, to P. Serna. Other devices and methods only indicate low or depleted agent supply. See, for example, U.S. Pat. No. 3,680,736, issued Aug. 1, 1972, to H. Viesmann and U.S. Pat. No. 5,076,315, issued Dec. 31, 1991, to J. A. King. Still other devices measure and report agent amount for monitoring purposes. See, for example, U.S. Pat. No. 4,830,757, issued May 16, 1989, to J. T. Lynch et al. and U.S. Pat. No. 5,427,694, issued Jun. 27, 1995, to L. E. Rugg.
Some devices include an alarm that is activated when an agent is depleted or attains a low level. See, for example, U.S. Pat. No. 3,655,050, issued Apr. 11, 1972, to R. L. Fifer. Some alarm devices even exploit magnetic phenomena. See, for example, U.S. Pat. No. 5,297,428, issued Mar. 29, 1994, to L. L. Carr et al.
Unfortunately, none of the foregoing provides for associating a solution at an infinitely-variable level and/or flow rate with respect to an agent or an agent amount indicator that also promotes agent-solution association. None of the aforementioned references, taken alone or in combination, are seen as teaching or suggesting the presently claimed Solution Treatment Agent Supply Apparatus.